Purpose
This guide explains how to connect two readers to a single door using a ButterflyMX 2 Door Controller by utilizing Reader Port 1 (Entry), Reader Port 2 (Exit), and Relay 2 (Dry) connected to REX 1.
Important Warning Each reader must be connected to its own reader port. |
Important Concept
- Each reader must be connected to its own reader port
- The door is controlled by Relay 1
- Reader 2 does not directly control the Door
- DRY Relay 2 must be used to trigger REX 1
System Architecture
Door:
Controlled by Relay 1
Reader 1 (Entry):
Connected to Reader Port 1
Reader 2 (Exit):
Connected to Reader Port 2
Uses Relay 2 (Dry) to trigger REX 1
Wiring Summary
| Entry Reader Side | Exit Reader Side |
| REX 1 | Relay 2 COM |
| REX 1 | Relay 2 NO |
Relay 2 DRY COM → REX 1
Relay 2 DRY NO → REX 1
Relay 1 COM WET → Lock
Relay 1 NO or NC WET → Lock
Procedure
- Connect Reader 1 to Reader Port 1.
- Connect the door lock to Relay 1 (Door).
- Connect Reader 2 to the Reader Port 2.
- Wire Relay 2 COM to REX 1.
- Wire Relay 2 NO to REX 1.
- Test Reader 1 for entry.
- Test Reader 2 for exit and verify door unlock.
How It Works
Reader 1 controls the door directly via controller logic.
Reader 2 triggers Relay 2, which closes a dry contact between COM and NO.
This sends a signal to REX 1, simulating a Request-to-Exit input and unlocking Door 1.
Troubleshooting
Reader 2 not unlocking door: Check Relay 2 wiring and configuration.
Door unlocks only from Reader 1: Verify REX 1 wiring.
No response on REX: Check terminal connections and continuity.
Best Practices
- Label Entry and Exit readers
- Use proper low-voltage wiring
- Keep wiring organized
- Test full workflow
- Document installation